When one printer is shared by a plurality of terminal devices, a method for using data processing apparatus is proposed so that an order for outputting data can be quickened or delayed in accordance with a request of a user (Refer, e.g. JP-A-6-187112). That is, when the user transmits data on file data, a name of a file and a priority to the data processing apparatus from the terminal device, the data processing apparatus transmits to the printer a print queue changed depending on the priority from a port different from a port for print data. Then, the printer performs a printing operation in accordance with the queue received from the data processing apparatus.
However, in the above-described technique, since the data on the priority is transmitted to the printer, there is a problem that the port different from the port for the print data needs to be provided. Further, since the data on the priority needs to be transmitted separately from the print data, a communication traffic to the printer is increased.
The present invention is proposed by considering the above-described problems and it is an object of the present invention to provide a print data processing apparatus and a printer in which a port for data on a control process does not need to be separately provided between the print data processing apparatus and the printer and a communication traffic can be reduced between the print data processing apparatus and the printer.